During the conversion of hepato-carcinogenic amines to excretable metabolites in liver cells, reactive, electrophilic species may be generated which bind to protein and nucleotide bases, causing structural and functional disturbances which may induce cancerous states. The primary objective of this research is to test the hypothesis that the reactive electrophilic intermediate directly responsible for the cancer-inducing action of carcinogenic amines is generated in a reaction subsequent to the formation of N-hydroxylated amine metabolites. Hydroxylamines will be generated in liver homogenates by the hepatoenzymatic reduction of keto-oximes under anaerobic conditions. The hepatic oxime reductases will be characterized and partially purified. Steady state kinetics of oxime reduction will be monitored using a high pressure liquid chromatographic procedure for separating the substrate from its metabolites. Isotopically labelled oxime substrates will be incubated with liver homogenates under anaerobic conditions to determine if hydroxylamines, generated during enzymatic reduction, can generate electrophilic alkylating species capable of binding with protein and polynucleotide bases. The metabolic fate of the hydroxylamine generated by oxime reductase will also be determined. Attempts will be made to ascertain whether a hydroxylamine oxidase is present in liver homogenates which can convert the hydroxylamine back to the starting oxime. If hydroxylamines are re-oxidized in liver, chemicals will be sought to try to minimize the reoxidation while maximizing oxime reduction. The metabolism of a series of acetophenone oxime derivatives will be studied to help determine the mechanism of reduction. The effect electron withdrawing and releasing moities exert on the rate of acetophenone oxime reduction will be investigated.